Oxide Substrate Effect Toward Electrocatalytic Enhancement of Platinum and Ruthenium–Selenium Catalysts

Abstract

Titanium dioxide (anatase) and carbon composites were produced. The oxide was synthesized via the sol–gel technique in a carbon matrix. A chemical interaction was revealed by thermal differential analysis since the carbon decomposition temperature shifts in the presence of the oxide. Oxide–carbon composites were used as support for nanodivided platinum and ruthenium–selenide catalyst. The nanoparticles were selectively deposited onto the oxide by means of electron–hole pairs generated on the oxide sites under UV irradiation. A systematic study for Pt was performed as a function of the loading using the oxide–carbon composite substrate and carbon toward the oxygen reduction reaction. A specific activity (mA/cm2 Pt) enhancement of 30% to 40%, at 0.9 V per reversible hydrogen electrode, with respect to carbon-supported samples, was obtained. This effect was also observed on the Ru–Se system and can be attributed to a catalyst–substrate effect.